I want to call phone number "#51234" in xcode use telprompt

I want to call phone number "#51234" in xcode use telprompt

first. sorry. i can't speak english well.
I want to call phone number "#51234" in xcode use telprompt.
but telprompt is reject it.
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:[NSString
stringWithFormat:@"telprompt://#5%@", nzoneNum]]];
nzomeNum is "1234"
I can't solve this problem.
please help me..